Approximate Count Distinct in Oracle Database 12c By Yuli Vasiliev Counting distinct values in a dataset is a commonly used operation in data analysis. In an Oracle Database, you can do this using function COUNT with the DISTINCT clause. Starting with Oracle Database 12cR1 (12.1.0.2), you can also use function APPROX_COUNT_DISTINCT, which – unlike COUNT with DISTINCT returning the exact […]

Count with Distinct By Yuli Vasiliev Function COUNT can be used with the DISTINCT clause, which makes COUNT consider only distinct values of the specified expression. There are several ways in which you can use COUNT with DISTINCT. This article covers them all, using as an example the part table that you will get as a result of reverse-engineering process […]

Including JSON in ODI 12c By Yuli Vasiliev ODI 12c comes with JSON support, meaning you can now use JSON as a data source. Unfortunately, the documentation does not offer a comprehensive example on how to do it. This article explains in detail how you can take advantage of this functionality, using as an example the PurchaseOrders.dmp coming with Oracle […]

Consolidating Diverse Data Sources With Oracle Database 12c By Yuli Vasiliev Oracle Database 12c cannot only store different types of data natively, but also allows you to access that data stored outside of the database. This article overviews some Oracle Database 12c features that allow you to consolidate diverse data sources located outside of the database. In particular, you’ll look […]

Using Oracle VM VirtualBox Templates By Yuli Vasiliev Are you seeking for a quick way to evaluate Oracle software? If so, why don’t you try Oracle VM VirtualBox templates providing a good way to familiarize yourself with new software stacks running within a virtual machine? Oracle VM VirtualBox templates represent pre-installed and pre-configured software images, which you can import into […]

The Quickest Way To Get Started With Oracle Database By Yuli Vasiliev If you already have any experience with installing an Oracle database in your system, you know that it can be quite a time-consuming task that requires you to complete a number of steps, including pre-installation and post-configuration ones. This can be especially disappointing if you just want to […]

By Yuli Vasiliev Can you really access Web data from your database? If you’re an Oracle database user, it is much easier than you think. The ability to access data stored outside of the database is one of those things that make Oracle Database unequivocally best in class. No matter where the data you need is located. No matter in […]

Using JSON_TABLE To Shred JSON Into Relational Data By Yuli Vasiliev Being less verbose than XML, JSON is becoming more and more popular as a data exchange format in Web services and Web applications today. Starting with release 12.1, Oracle Database supports JSON, letting you access JSON content stored either inside or outside of the database. The example provided in […]

Shredding XML Into Relational Rows   By Yuli Vasiliev This article reveals how you might use SQL/XML functions in your SQL statements to access XML data, shredding it into relational rows and then joining them with regular relational data stored in an Oracle database. In particular, it explains how you might use SQL/XML function XMLTable to derive relational data from […]